There are many biopsy procedures in which tissue samples are taken for later histology. In "cold" biopsy procedures, surgical forceps are inserted within, for example, an endoscope, and are used to resect (i.e., cut) a tissue sample from, for instance, the biliary tree or colon. The forceps, and, hence, the tissue sample, are then removed from the patient through the endoscope.
Extensive bleeding can occur as a result of cold resecting, which can lead to dangerous blood loss levels. Hence, after the tissue sample is removed, another device can be inserted into the patient through the endoscope to stop the bleeding. These devices include tamponade devices which apply pressure to the bleeding site to stop the bleeding, devices which apply alcohol to the bleeding site to stop the bleeding, and electro-cautery devices which apply radio frequency (RF) energy to one or more electrodes (monopolar or bipolar) in contact with the bleeding site to cauterize the tissue and stop the bleeding. Following resecting, time is required to remove the forceps and tissue sample and insert a device to stop the bleeding. During this time, the resecting site continues to bleed.
Alternatively, a "hot" biopsy procedure is performed using surgical forceps in which the jaws are electrodes (bipolar or monopolar). After the tissue sample is resected, the forceps are brought in contact with tissue remaining at the resecting site and RF energy is applied to the forceps to cause current to flow (i.e., cauterization) through the resecting site tissue to coagulate the tissue and stop the bleeding. Coagulation of the tissue may also kill cancerous or precancerous tissue at the resecting site. Often, RF energy is applied to the forceps during resecting to help cut the tissue sample as well.
The tissue sample is again removed from the patient through the endoscope for histology. The tissue sample, however, may be inadvertently cauterized when the resecting site is cauterized rendering the tissue sample unusable for histology, e.g., the question of cell malignancy cannot be answered. The forceps may be lined with insulating material to electrically isolate the tissue sample from the forceps. However, heat generated when the resecting site tissue is cauterized may coagulate the tissue sample within the forceps, again, rendering the tissue sample unusable for histology.